Apparatus for forming a collapsible container

ABSTRACT

An apparatus for collapsing and folding an upright container to a compact stackable configuration, the container having a bottom wall, peripheral side wall with at least upper, lower and intermediate annular stepped portions in the peripheral side wall, and a top wall having a discharge opening therein, includes tooling for supporting and holding the container in an upright position; a first forming element for engaging and exerting a downward force on the intermediate annular stepped portion of the peripheral side wall and for effecting the formation of a first folded portion in the peripheral side wall; and a second forming element for engaging and exerting a downward force on the top wall for effecting the formation of a second folded portion in the peripheral side wall, substantially concentric with and radially adjacent the first folded portion.

This is a division of application Ser. No. 07/828,473, filed Jan. 30,1992, now U.S. Pat. No. 5,206,037, which is a division of Ser. No.07/576,080, filed Aug. 31, 1990, now U.S. Pat. No. 5,224,613.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates generally to plastic bottle or containerconstructions, and particularly to thin walled bottles or containerswhich are collapsible and foldable, as well as to a process andapparatus for collapsing such bottles or containers.

In the container industry, there are a number of known applications forrelatively thin, flexible bottles or containers, some of the more wellknown of which relate to the shipment and retail sale of beverages suchas milk, water, juice, etc., as well as liquid or powdered cleaners,detergents and the like.

It is often the case that such containers must be shipped overconsiderable distances to distributors who fill and then ship the filledcontainers to retail concerns. During the initial shipment todistributors, the empty containers, for example one gallon containers,take up so much space that, from a volume standpoint, the manufactureris shipping mostly air.

At the same time, there is great concern in the environmental arena forplastic materials which for the most part are not biodegradable, andwhich therefore pose significant disposal problems, particularly inlight of the ever expanding utilization of plastics in virtually everyarea of technology. The problem is especially acute in the containerindustry.

This invention seeks to alleviate both of the above described concernsby:

1) providing a plastic bottle or container construction which requiresapproximately one half of the plastic currently used in most plasticcontainers, particularly those which typically carry milk, water, juice,detergents (liquid or powder) and other liquids and/or particulates; and

2) shaping the containers in such a way as to facilitate collapse andfolding to a compact size which results in a four or more to oneincrease in shipping capacity.

For purposes of this invention, the term "container" refers to plasticcontainers or bottles having shapes as disclosed herein. In accordancewith a preferred embodiment of the invention, a thin walled plasticcontainer is manufactured by an extrusion or injection blow moldingprocess, incorporating a thin walled construction which permits thenormally self-supporting container to be collapsed and a portion orportions concentrically folded to provide a compact, nestable and/orstackable container for efficient shipment.

The container side wall in a preferred embodiment is provided withperipheral, vertically spaced steps or shoulders which facilitate axialcollapse and subsequent concentric folding of portions of the side wallto provide a collapsed and folded container article with at least four"layers" of side wall arranged in a zig-zag or S-shaped configuration,in generally surrounding relationship to tapered shoulder and narrowneck portions of the container.

The container side wall may also be formed originally with one or moresteps, or with a smooth, tapered or even straight peripheral side walland nevertheless collapsed and folded as will be explained furtherherein.

A plurality of containers collapsed and folded in the manner describedabove may be arranged in the form of a stack for easy and efficientshipment.

There is also disclosed for eventual use with the preferred embodimentof the invention a relatively rigid open-topped pitcher for receivingand holding the plastic container. The pitcher is formed with interiorbeads and/or steps about its periphery, which are designed to engage thecorresponding steps or shoulders on the container side wall to therebyhold the container in place during pouring.

An exemplary embodiment of an apparatus utilized to carry out thecollapsing and folding operation includes a container holder andreciprocable fluid actuated tool members which act in sequence to formfirst and second folded portions of the container. More specifically,one exemplary embodiment of the apparatus includes a container holderdevice, opposing elements of which are reciprocable between open andclosed positions, and adapted to hold or support a container during acollapsing and folding operation. The holder is mounted on a supportingsurface provided with an opening through which an associated containermay be brought into position. The supporting surface is also providedwith one or more stops for limiting downward movement of acontainer-engaging tool element as described in greater detail below.

The apparatus also includes a tool frame comprising a stationary platensupported on a plurality of columns in vertical alignment with thecontainer holder -device. The stationary platen mounts a main doubleacting cylinder assembly. A lower piston rod portion (which is oftubular construction) extends through the stationary platen and issecured to an inner container-engaging pusher member. An outer containerengaging pusher member or sleeve is concentrically located relative tothe inner pusher member and is held in resilient spaced relationshipthereto by guide bars and a pair of side cylinder assemblies, thecylinders of which are secured to the inner pusher member and the pistonrods of which are secured to the outer pusher member.

The inner pusher member includes a movable upper platen provided with asubstantially cylindrical lower portion having a tapered annular surfacewhich is adapted to engage the tapered shoulder portion of thecontainer.

The outer pusher member or sleeve includes a movable lower platenprovided with an annular skirt portion movable in telescopingrelationship with the cylindrical lower portion of the inner pushermember. The lower edge of the depending skirt portion is adapted toengage the container sidewall as further described herein.

The lower movable platen is adapted to engage the one or more stopsprovided on the supporting surface to limit downward movement of theouter pusher member, while the lower movable platen itself serves as astop to limit the relative downward movement of the inner pusher memberand its associated upper movable platen.

An upper tubular piston rod portion of the main double acting cylinderis fixedly secured at its distal end to a lower horizontal element of anopen rectangular frame. A top cylinder assembly is fixedly secured to anupper horizontal element of the open rectangular frame, with the pistonof the top cylinder extending through the upper frame element andconnected to an upper side of a pancake cylinder assembly, so that thepancake cylinder assembly is reciprocable within the open rectangularframe, independent of the main cylinder. The lower side of the pancakecylinder assembly mounts an air adaptor manifold (including an air inletand an outlet) which in turn is connected to an air tube which extendsdownwardly through the tubular main piston and through the stationary,upper and lower platens to a recessed area within the center of theinner pusher member. At the same time, the pancake cylinder has a smalldiameter rod attached to (or integral with) its own piston rod whichextends downwardly through and below the lower end of the air tube.

The lower end of the tube is fixed to an upper washer or bushing and thelower end of the rod is fixed to a lower washer or bushing. Between thetwo washers or bushings, there is located a resilient, expandable plug,shaped and sized to fit within the discharge opening of a container. Thelower bushing also is provided with apertures for introducing air fromthe air tube to the interior of the container, and for exhausting airfrom the container during the collapsing and folding operation.

The operation of the above described apparatus is explained brieflybelow, and in more detail further herein.

Initially, a series of containers may be fed, one at a time, on aconveyor or the like structure to a location beneath an apertureprovided within the supporting surface of a work table. At thislocation, lateral movement of the containers may be halted and the maincylinder assembly actuated to move the inner and outer pusher members totheir downwardmost position, along with the open rectangular frame andassociated pancake cylinder and top cylinder. Once the components are intheir fully lowered position, the top cylinder is actuated to extend thepancake cylinder and tube and rod members to a loading position wherethe resilient plug is located below the work table. In a fully automatedsystem, the downward movement of the plug would terminate with the pluglocated in the discharge opening of the container. In a semi-automaticsystem, the container may be loaded manually onto the plug. The pancakecylinder itself is then actuated to retract the rod, thereby pulling thelower bushing upwardly relative to the upper bushing to thereby forcethe resilient plug to expand radially outwardly to simultaneously gripthe container and seal the discharge opening thereof. Thereafter, thetop cylinder is retracted to draw the container upwardly into theaperture provided in the work table, and the main cylinder is thenactuated to draw the inner and outer pusher members, along with the plugand attached container, upwardly so that all components are in theirupwardmost position and the container is situated immediately above thesupporting surface.

The container holder device is then closed to provide support for thecontainer and to hold the latter in precise alignment during thecollapsing and folding operation. In this position, the lower edge ofthe outer pusher member is located closely adjacent or in engagementwith, an intermediate one of the three annular steps on the containerside wall.

Air at very low pressure is then introduced into the interior of thecontainer through the tube extending from the resilient plug to the airmanifold at the pancake cylinder assembly. This insures that thecontainer will be in a normal fully blown condition with no creases orwrinkles which might otherwise interfere with the collapsing/foldingoperation.

The air manifold is then opened to permit the controlled escape of airfrom the container as the deforming operation commences. At this time,the main cylinder is actuated to move the inner and outer pusher membersdownwardly while the pair of side cylinders maintain a predetermineddistance between the upper and lower movable platens of the inner andouter pusher members, respectively. In other words, the side cylindersact as springs, biasing the inner and outer pushers apart. In apreferred embodiment, the outer pusher member engages and pushesdownwardly on the intermediate step on the peripheral wall of thecontainer and initiates a first fold which is completed when the lowermovable platen abuts the limit stops provided on the supporting surfaceof the work table. Continued downward movement of the lower pistonportion of the main cylinder overcomes the side cylinder forces tendingto keep the upper and lower platens apart, so that the inner pushermember engages the shoulder portion of the container, pushing itdownwardly to initiate a second folded portion in the peripheral sidewall of the container, radially inward and adjacent the first foldedportion. This second folded portion is completed when the upper movableplaten abuts the lower movable platen.

If desired, the collapsing/folding operation may be terminated at thisstage and, upon opening (or retraction) of the container holder andextension of the top cylinder piston, the container is pushed downwardlyaway from the inner and outer pusher members, and the pancake cylindermay again be actuated to extend the rod and lower bushing downwardly,thereby causing the resilient plug to contract, enabling the completedcontainer to be removed from the apparatus.

In an alternative arrangement, upon completion of the first and secondfolds by the inner and outer pusher members, and prior to the extensionof the pancake cylinder piston, the top cylinder may be actuated topartially extend its piston to thereby push the resilient plugdownwardly, thereby also pushing the discharge portion of the containerdownwardly within the confines of the first and second folds so that thedischarge opening does not extend above the uppermost edge of the foldedportions. Following opening of the container holder, further extensionof the top cylinder and extension of the pancake cylinder rod-.wouldthen enable removal of the container in the manner described above.

Thus, in one aspect, the present invention relates to a collapsed thinwall container for facilitating compact shipment of a plurality of suchcontainers comprising a bottom wall, a peripheral side wall extendingfrom said bottom wall, a tapered shoulder section extending from theperipheral side wall, and a reduced diameter neck portion including adischarge opening extending from the tapered shoulder section, and theperipheral side wall including at least one portion folded outwardly andupwardly to form a first concentric folded portion extending upwardly atleast to the tapered shoulder section.

In another aspect, the present invention relates to a stack ofcontainers of the type described above.

In a related aspect, the present invention relates to a thin wallednormally self-supporting flexible container of unitary constructionhaving a bottom wall, a peripheral side wall, and a top wall which mayinclude a tapered shoulder section and a reduced diameter neck portionprovided with a discharge opening, the improvement comprising aplurality of vertically spaced annular steps formed in the side wall,each step causing the peripheral side wall portion immediately above thestep to have a smaller diameter than the peripheral side wall portionimmediately below the step, the steps adapted to permit the container tobe collapsed and folded to a compact configuration wherein a pair ofconcentric folded peripheral side wall portions lie radially adjacenteach other and adjacent the tapered shoulder and reduced neck portionsof the container.

In another aspect, the present invention relates to an apparatus forcollapsing and folding an upright container comprising, broadly, meansfor supporting and holding the container in an upright position; firstforming means for engaging and exerting a downward force on theintermediate annular stepped portion for effecting the formation of afirst folded portion; and second forming means..for engaging andexerting a downward force on the tapered shoulder portion for effectingthe formation of a second folded portion.

Finally, the present invention relates to a method of forming acollapsed and folded container broadly comprising the steps of:

a) providing a normally self-supporting, flexible container of unitaryconstruction and having a bottom wall, a peripheral side wall extendingfrom the bottom wall and a top wall which may include a tapered shouldersection extending from the peripheral side wall, and a reduced diameterneck portion extending from the tapered shoulder portion and including adischarge opening;

b) forming a first folded portion by pushing a first portion of theperipheral side wall downwardly toward the bottom wall; and

c) forming a second folded portion by pushing the tapered shouldersection downwardly toward the bottom wall after the completion of stepb).

It will be understood that the container itself may have a differentshape than that described above. For example, the container top wall maybe flat, with a smaller or larger discharge opening therein. In thiscase, the described method and apparatus would be modified accordingly.

From the above, it will be appreciated that the present inventionprovides significant benefits in terms of shipping and storage capacityand efficiency while, at the same time, provides for substantial savingsin the amount of plastic used in the manufacture of plastic containers,the latter having a further beneficial effect in the matter of wastedisposal.

Other objects and advantages of the invention will become apparent fromthe detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cross sectional side view of an upright container inaccordance with an exemplary embodiment of the invention;

FIG. 2 is a cross sectional side view of a stack of containers of thetype illustrated in FIG. 1 but collapsed and folded in accordance withthe invention;

FIG. 3 is a side view of a container in accordance with a secondexemplary embodiment of the invention;

FIG. 4 is a side cross sectional view of a container of the typeillustrated in FIG. 3, collapsed and folded in accordance with theinvention;

FIG. 5 is a partial cross sectional side view of a container inaccordance with a third and preferred embodiment of the invention,supported within a relatively rigid outer pitcher;

FIG. 5A is a partial cross sectional side view of the containerillustrated in FIG. 5 but supported within a box;

FIG. 6 is a partial cross sectional side view of a stack of containersof the type illustrated in FIG. 5, collapsed and folded in accordancewith the invention;

FIG. 7 is a perspective view of an apparatus for collapsing and foldingcontainers in accordance with the invention;

FIGS. 8-15 are partial side cross sectional views of the apparatusillustrated in FIG. 7, in various stages of operation during acollapsing and folding operation of the container of the typeillustrated in FIG. 5; and

FIG. 16 is a cross sectional side view of the apparatus in FIGS. 7-15,and showing an additional collapsing of the discharge portion of thecontainer in accordance with another and preferred embodiment of theinvention.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference to FIGS. 1 and 2, a thin walled, one gallon plasticcontainer 10 in accordance with an exemplary embodiment of the inventionincludes a bottom wall 12, a peripheral side wall 14, and a top wallwhich may comprise a tapered shoulder portion 16, and a narrow neckportion 18. The neck portion 18 may be provided with a radiallyoutwardly directed flange 20 and a series of threads 22 at the uppermostend of the neck portion surrounding a discharge opening 24. The threads22 are designed to receive a conventional screw type closure (notshown).

In a preferred embodiment, the bottle or container is a unitarystructure formed by extrusion or injection blow molding or otherconventional plastic forming process. The finished side wall 14 has apreferred thickness between 0.004 and 0.010 of an inch, and the neckportion 18 has a preferred thickness between about 0.010 and 0.030 of aninch. The bottom wall 12 has a thickness substantially the same as theside wall 14, i.e., between 0.010 and 0.025 of an inch, but it may beslightly thicker as a result of the pinching off of the parison prior toblowing. Other thickness ranges are possible for the various containerportions, the significant criteria being that the bottle be normallyself-supporting but easily collapsed and folded in the manner describedbelow.

One gallon containers formed with the above dimensions represent anapproximate 50% reduction in the amount of plastic material required, ascompared to conventional milk containers. Similar savings can beexpected with containers of other sizes as well.

Suitable semi-rigid (or more flexible) plastics including high densitypolyethylene (HDPE) and PET may be used for the liner, but linear lowdensity polyethylene (LLDPE) is presently preferred.

In one exemplary embodiment, the peripheral side wall of the bottle orcontainer is provided with an annular step or shoulder 26 to facilitatethe collapsing and folding operation.

With reference now to FIG. 2, a stack 28 of thin walled bottles 10 isillustrated, with each container 10 collapsed to a stackable andnestable configuration. As shown in FIG. 2, each container includes aninwardly domed portion 30 and an outwardly and upwardly foldedconcentric portion 32 extending to an uppermost tip 36 which lies withinthe plane of the tapered shoulder portion 16 of the container 10. Theinwardly and upwardly domed portion 30 extends into the tapered shouldersection 16 so that a recess 38 is formed in the lower portion of thecontainer for receiving the neck portion 18 and part of the taperedshoulder portion 16 of adjacent container 10'. A series of suchcollapsed and folded containers may be stacked and nested as shown inFIG. 2 so as to conserve significant space during shipping and/orstorage prior to filling.

With reference now to FIG. 3, another plastic container configuration inaccordance with a second exemplary embodiment of the invention isillustrated. This second container 40 includes a bottom wall 42, aperipheral side wall 44, a tapered shoulder area 46 leading to a reduceddiameter neck portion 48. Within this reduced diameter neck portion isprovided a radially enlarged flange 50 and an uppermost portionincluding a threaded closure receiving portion 52 surrounding adischarge opening 54. As in the previously described embodiment, aconventional screw type or snap-on closure (not shown) may be utilizedin conjunction with the container 40.

This second exemplary embodiment of the invention is generally similarto the first described embodiment with the principal distinctionrelating to the formation of a plurality of annular steps or shoulders56, 58, 60 and 62 in vertically spaced relationship along the peripheralside wall 44 of the container. These steps or shoulders serve to enlargethe diameter of the container in each adjacent lower portion, so thatdifferent diameter side wall portions 64, 66, 68, 70 and 72 are createdby the series of steps or shoulders, to create an overall slightlytapered appearance.

The bottle as shown in FIG. 3 may be collapsed to the configurationshown in FIG. 4, with each of the steps 56, 58, 60 and 62, facilitatingthe formation of adjacent and concentric folded portions 56a, 58a, 60aand 62a, respectively. If desired, the shoulder section 46 may also beessentially inverted to the upward and outward configuration shown at46a. By this arrangement, the neck portion 48 lies substantially flushwith, or slightly below the uppermost edges of the folded portions 56a,58a, etc., to provide an even more compact stacking arrangement.

Turning to FIG. 5, a container 74 in accordance with a third andpresently preferred embodiment of the invention is disclosed andincludes a bottom wall 76, a peripheral side wall 78, and a taperedshoulder portion 80 leading to a reduced diameter neck portion 82.Within the reduced diameter neck portion, there is a radially enlargedflange 84 and an uppermost portion including a threaded closurereceiving portion 86 surrounding a discharge opening 88. As in thepreviously described embodiments, a conventional screw-type (or snap-onclosure, not shown) may be utilized in conjunction with the bottle 74 ina conventional manner.

This preferred embodiment of the invention is provided with an annulargroove 90 and a pair of annular steps or shoulders 92 and 94 formed invertically spaced relationship along the peripheral side wall 78 of thecontainer. As in the previously described embodiment, the presence ofgroove 90 and steps or shoulders 92 and 94 serve to enlarge the diameterof the bottle in each adjacent lower portion so that different diameterside wall portions 96, 98 and 100 are created by the groove 90 and stepsor shoulders 92 and 94.

It has been discovered that the container need not have the describedone or more steps formed in the peripheral sidewall. Another workablearrangement is provided by a smooth tapered peripheral sidewallextending from a smaller diameter upper portion to a larger diameterlower portion.

It has also been found that a smooth substantially cylindrical sidewallcan be collapsed and folded in accordance with this invention byintroducing pressurized air into the container interior to bulge thesidewall radially outwardly so as to provide a surface engageable by thefolding tool, as will be described further below.

In FIG. 5, the container 74 is shown inserted within a pitcher 102. Thepitcher 102, which is preferably made of relatively rigid plasticmaterial, is formed with a bottom wall 104, a lower peripheralsupporting bead 106 and a peripheral side wall 108 extending upwardly toan outwardly flared edge 110. The pitcher is also formed with aninwardly directed annular bead 112 and a pair of annular steps 114 and116 which are located to align with and engage the corresponding groove90 and steps or shoulders 92 and 94, respectively formed on thecontainer. In this manner, the container 74 is retained within thepitcher 102 during pouring motions.

The pitcher 102 can be formed in a one-piece configuration, or it can beformed with a separately attached bottom wall spin welded, solventbonded or otherwise suitably secured to the peripheral side wall.Mechanical engagements between the bottom wall and side wall such as asnap engagement are also contemplated. In the event container 74 is usedalone, without the pitcher 102, the groove 90 in the container side wallmay be formed as a step similar to those shown at 92, 94.

It will be appreciated that the filled container can be used alone, witha pitcher such as that shown at 102, or with any number of other pitcherconfigurations. The filled container can, of course, be used incombination with a variety of outer package arrangements such as boxes,or the like. FIG. 5A illustrates the use of an essentially rectangularpaperboard or cardboard box 103 as a "carrier" for the container 74.

With reference now to FIG. 6, a stack 118 of collapsed and foldedcontainers of the type illustrated in FIG. 5 is shown in a ready-to-shipconfiguration. Specifically, by collapsing and folding the containers inthe manner described hereinbelow, peripheral folded side wall portions120 and 122 are arranged about a fold edge 124 to form a firstconcentric folded portion, and peripheral side portions 126 and 128 arearranged about a fold edge 130 to form a second adjacent folded portion.This second folded portion lies radially inwardly of the first foldedportion and connects via a fold 132 to the tapered shoulder portion 80of the container 74. Thus, a collapsed and folded peripheral side wallis provided which includes four adjacent layers or thicknesses in azig-zag or S-shaped arrangement generally surrounding the taperedshoulder section 80 and reduced diameter neck portion 82 of thecontainer 74. The fold edges 124, 130 lie substantially flush with theupper portion of the radial flange 84 formed in the reduced diameterneck portion 82.

In stack form, the bottom wall 76 of each container 74 is supported onthe peripheral edge of the discharge opening 88 of the next adjacentcontainer to thereby provide a compact arrangement which significantlyincreases shipping and/or storage efficiency.

In a modification of the above described container, the tapered shouldersection 80 may be at least partially collapsed, as shown in FIG. 16, sothat the uppermost fold edges 124, 130 of the first and second foldedportions are in substantial lateral alignment with the discharge opening88 to facilitate an even more compact stacking arrangement where thebottom wall 76 of one container rests on the peripheral edge of thedischarge opening 88 as well as fold edges 124, 130.

With reference now to FIGS. 7 through 16, an exemplary apparatus isillustrated-for carrying out a method of collapsing and folding a bottleor container of the type illustrated in FIG. 5 to the folded andcollapsed configuration shown in FIG. 6.

Specifically, referring to FIG. 7, the apparatus 140 is supported on awork table 142 or other suitable structure having a substantially flatsupporting surface 144 and an aperture 145 of sufficient diameter topermit a container to pass therethrough, as explained in greater detailbelow.

A container holder device 146 for supporting the container during thecollapsing and folding operation is mounted on the supporting surface144, and includes a pair of opposed elements 148, 150 which are slidablymounted on guide bars 152, 154 for reciprocal movement toward and awayfrom each other. The element 148 has a substantial semi-cylindricalconfiguration including a container supporting surface 156 and anupstanding peripheral wall 158. The supporting wall 156 is provided witha semi-circular cut-out portion 160. The other base supporting element150 has a configuration substantially identical to the base element 148so that when the two base elements engage, a substantially cylindricalsupporting structure having an open end and a closed end is provided forsupporting and confining the container.

Piston and cylinder assemblies 162, 164 are provided, with respectivepiston rods 166, 168 fixed to an associated one of the elements 148, 150for moving the elements 148, 150 linearly along the guide rods or bars152, 154 between open and closed positions.

The guide rods 152, 154 are suitably secured at either end withinsupport blocks 170, 172 and 174, 176, respectively.

It will be appreciated that other container holder devices orarrangements, driven pneumatically or electrically, can be used tosupport the container.

Collapsing and folding tool elements are supported above the worksurface 144 on a stationary platen 178 supported by a set of four tiebars, three of which are shown in FIG. 7 at 180, 128 and 184 which arerigidly secured at first ends to the table 142, and at second ends tothe stationary platen 178 by bolts or other suitable fastening means186. The stationary platen 178 is located sufficiently above the worksurface 144 to permit a bottle or container of the type illustrated inFIG. 5 to be supported on the container holder 146 for folding andcollapsing into the configuration shown in FIG. 6. Platen 178 isprovided with a pair of cut-outs or notches 188 along opposite edges ofthe platen for reasons described below.

A main cylinder assembly 190 is supported on the platen 178 by anysuitable means. This is a double acting cylinder assembly, with tubularpiston rod portions 192, 194 (see FIG. 8) extending from the top andbottom, respectively, of the main cylinder 190. The upper tubular pistonrod portion 192 is fixedly secured (by threaded engagement or othersuitable means) to a lower horizontal member 196 of an open rectangularframe 198, which includes the lower horizontal member 196, an upperhorizontal member 200 and a pair of side elements 202, 204.

A top cylinder assembly 206 is secured to the upper horizontal member200 by any suitable means, and includes a piston rod 208 which extendsthrough the member 200 and is fixed to an adaptor 210 which, in turn, isconnected to a pneumatic pancake cylinder 212. The cylinder 212 isattached at its lower end to an air supply manifold 214. With referenceto both FIGS. 7 and 8, it will be seen that a hollow tube 216 extendsfrom the air supply manifold 214, through the upper and lower tubularpiston rod portions 192, 194 and is fixed at its lower end to an upperbushing 218. The piston rod 220 (and/or integral or joined extensionthereof) of the pancake cylinder 212 passes through the tube 216 and isfixed to a lower bushing 222. Located between the upper and lowerbushings 218, 222, there is an expandable, rubber (or other resilientsynthetic material) plug 224 which serves to engage and seal thedischarge opening of the container as will be described further below.

As best seen in FIGS. 8 and following, the lower end of the lowertubular piston rod portion 194 of the main cylinder assembly 190 isfixed to a first inner container engaging pusher member 226 by suitablemeans, such as screws 228 or the like. The inner pusher member 226includes an upper movable platen 230 and a substantially cylindricallower portion 232 which is formed with an annular tapered surface 234 atits lowermost end which is adapted to engage the shoulder portion of thecontainer. The lower cylindrical portion 232 is also formed with acentral recess 236 which receives the expandable plug 224 when thepiston rod 208 of the cylinder 206 is in its uppermost or retractedposition.

A pair of identical side cylinder assembles 238 are mounted at oppositeends of the upper movable platen 230, and have piston rods 240 whichextend through the upper movable platen 230 and are fixed (by threadingor other suitable means) to opposite ends of a lower movable platen 242of a second outer container engaging pusher member 244 which isconcentrically arranged relative to the inner pusher member 226.

The outer pusher member or sleeve 244 comprises the lower movable platen242 and a depending annular skirt portion 246 having a lower annularedge 248.

A plurality (preferably four) stop pins 250 are fixed to the supportsurface 144, in alignment with the lower movable platen 242 to provide astop limiting downward movement thereof. Other stop arrangementsincluding a solid ring may be employed. The upper movable platen 230 isalso aligned with the lower movable platen 242 so that the latter limitsdownward movement of the former as described below.

A plurality of guide bars 252 may be utilized to insure straight linereciprocatory movement of the inner and outer pusher members 226, 244,the guide bars 252 being fixed to the upper side of the lower movableplaten 242 and extending through the upper movable platen 230 and thestationary platen 178, as best seen in FIG. 7.

The manner in which the above described apparatus functions to collapseand fold a bottle or container in accordance with an exemplaryembodiment of the invention will now be described in detail.

With reference again to FIG. 7, a conveyor 254, or other suitableworkpiece transport means, may be utilized to feed a plurality ofcontainers 74 to the collapsing and folding apparatus 140. For example,the conveyor 254 can be arranged to feed the containers below the table142 to a position directly beneath the aperture 145. The position of thevarious components including the container 74 in this initial positionis shown in FIG. 8.

In a less automated system, the containers may be manually locatedbeneath the aperture 145 on a lower work table surface (not shown).

With reference to FIG. 7, the main cylinder assembly 190, provided withinlet and outlet lines 256, 258, is shown with its tubular piston rodportions 192, 194 in their upwardmost position. Thus, the upper movableplaten 230 is shown in engagement with the stationary platen 178 whilethe lower movable platen 242 is maintained at a predetermined spaceddistance below the upper movable platen 230 by the side cylinderassemblies 238 (provided with inlet and outlet lines 260, 262) which arein their fully extended position. At the same time, the top cylinderassembly 206, provided with inlet and outlet lines 264, 266, is also ina retracted position so that the expandable plug 224 is received withinthe recess 236 formed in the cylindrical portion 232 of the inner pushermember 226.

With reference now to FIG. 8, prior to loading the container 74 onto thesurfaces 156 of the container holder assembly 146 (omitted from FIG. 8for clarity), the main cylinder assembly 190 is actuated to move itstubular piston rod portions 192, 194 to their downwardmost position. Indoing so, the top cylinder 206 and the open rectangular frame 198 arealso moved to a lowermost position. At the same time, the lower pistonrod portion 194 moves the inner and outer pusher members 226, 244downwardly until the lower movable platen 242 engages the stop pins 250.At this point, the lower piston rod portion 194 continues to movedownwardly, overriding the resistance of the side cylinders 238 so thatthe inner pusher member 226 continues downwardly until the upper movableplaten 230 engages the lower movable platen 242.

With the discharge opening of the container 74 in vertical alignmentwith the expandable plug 224, the top cylinder 206 is then actuated toextend the tube 216 and rod 220 downwardly until the expandable plug 224is exposed below the work table 142 as shown in FIG. 9. The container 74may then be manually pushed onto the plug 224, with the plug insertedwithin the discharge opening 88. In a fully automated system, extensionof plug 224 could be timed with the arrival of the container 74 viaconveyor 254, and the plug would then be inserted directly andautomatically into the opening 88 via actuation of the top cylinder 206.

In any event, once the plug 224 is located within the discharge opening88 (FIG. 9), the pancake cylinder assembly 212, provided with an inletline 268 and outlet line 270, is actuated to retract the rod 220,thereby drawing the lower bushing 222 toward the upper bushing 218,causing the plug 224 to expand radially outwardly into gripping andsealing relationship with the reduced diameter neck portion 82 of thecontainer 74 (as shown in FIG. 10).

With reference now to FIGS. 10 and 11, the top cylinder assembly isreversed to draw the expandable plug 224 along with the container 74upwardly into the aperture 145. Simultaneously, or shortly thereafter,the main cylinder assembly 190 is actuated to move its piston rodportions 192, 194 along with inner and outer pusher members 226, 244 aswell as plug 224 (and the now attached container 74) upwardly into theiroriginal position as illustrated in FIG. 7.

The cylinders 162 and 164 of the container holder assembly 146 are thenactuated to move the split holder sections 146, 150 into supportingengagement beneath the container 74 as partially illustrated in FIG. 11.

Air is then supplied from the manifold 214 via line 264 into the spacebetween tube 216 and rod 220 downwardly through the center of the plug224 and through apertures 272 provided in a lower bushing 222 into theinterior of the container 74, as indicated by the arrows in FIG. 11. Theair supplied to the container is preferably at very low pressure, forexample 0.2 to 2 psi (preferably about 0.3 psi) and insures that thereare no wrinkles, creases or dents in the container 74 which wouldotherwise interfere with the collapsing/folding operation.

It will be appreciated that just prior to collapsing/folding, the airmanifold 214 must be opened to permit the controlled escape of airduring the folding and collapsing operation (as indicated by the arrowsin FIGS. 12, 13, etc).

With reference again to FIG. 11, the container 74 is shown in positionfor the collapsing and folding operation to commence. In this regard, itis noted that the lowermost edge 248 of the outer pusher member 244 liesimmediately adjacent or in engagement with the intermediate peripheralstep 92 on the peripheral side wall 78 of the container 74.

Referring now to FIG. 12, actuation of the main cylinder assembly 190causes both the inner and outer pusher members 226, 244, respectively,to move downwardly. This is because the outer pusher member is supportedby reason of the side cylinder assemblies 238 on the upper movableplaten 230. During this initial downward movement of the lower tubularpiston rod portion 194 of the main cylinder assembly 190, the inner andouter pusher members 226, 244 are maintained a predetermined spaceddistance apart by the biasing force of the piston rods 240 of thecylinder assemblies 238.

As the lower edge 248 of the outer pusher member 244 pushes downwardlyon the annular step 92 of the side wall 78, the first folded portion isformed about edge 124 between the depending cylindrical skirt portion246 and the inner cylindrical surface of the container holder assembly146. During this collapsing and folding step, the axial length of thecontainer 74 will shorten so that as the inner pusher member 226 followsor rides along with the outer pusher member 244, the latter does notexert any axial pressure on the tapered shoulder section 80 of thecontainer 74. Also during this initial forming step, and as noted above,air is exhausted in a controlled manner from the interior of thecontainer 74 through the apertures 272 and tube 216 as indicated by thearrows in FIG. 12.

Turning now to FIG. 13, the outer pusher member 244 is shown to havereached its lowermost position, where the lower movable platen 242 hasengaged the stop pins 250 and with the first folded portion completed.As the lower tubular piston rod portion 194 continues to movedownwardly, the force exerted by the main cylinder assembly 190overcomes the opposing resistive forces of the cylinder assemblies 238so that the inner pusher member 226 continues downward movement relativeto the now stationary outer pusher member 244. With reference to FIGS.14 and 15, during this continued downward movement of the inner pushermember 226, the tapered surface 234 engages the tapered shoulder portionof the container and pushes the container downwardly to effect a secondfolded portion about a fold edge 130, between the outer peripheralsurface of the cylindrical portion 232 of the inner pusher member 226and the inner peripheral surface of the depending skirt portion 246 ofthe outer pusher member 244. The upper and lower shoulders or steps 90(groove 90 is shown as a step here), 94, respectively, formed in thecontainer side wall 78, serve to facilitate the collapsing and foldingaction during this second forming step.

When the upper movable platen 230 of the inner pusher member 226 hasbottomed out against the lower movable platen 242 of the outer pushermember 244, as best seen in FIG. 15, the second folded portion of theperipheral side wall 78 is completed. This second folded portion liesconcentrically adjacent and radially inwardly of the first foldedportion with the uppermost fold edges 124, 130 at substantially the sameheight.

At this stage of the operation, the container holder device 146 may beopened or retracted, and the top cylinder 206 actuated to extend thetube 216 and rod 220 downward to push the collapsed and folded containeraway from the inner and outer pusher members 226, 244. Thereafter, thepancake cylinder assembly 212 may be actuated to extend the rod 220 tothereby contract the expandable plug 224 so that the collapsed andfolded container may be removed from the apparatus.

It may advantageous, however, to effect an additional collapsing step asillustrated in FIG. 16. Thus, after the lower piston rod portion 194 ofthe main cylinder assembly 190 has reached its lowermost position withboth inner and outer pusher members 226, 244 as shown in FIG. 16, thetop cylinder 206 may be actuated to partially extend the tube 216 androd 220 so that the expandable plug 224 is driven downwardly to at leastpartially collapse the tapered shoulder section 80 of the container 74to thereby position the discharge opening 88 of the container 74 atapproximately the same height as the uppermost edges 124, 130 of thefirst and second folded portions. This arrangement permits an even morecompact and efficient stacking arrangement for shipment and/or storagepurposes. Removal of the container would then be achieved as describedabove.

It is also within the scope of this invention to modify the interiorsurface 234 of the inner pusher member 226 so that the tapered shouldersection 80 of the container 74 is at least partially collapsed duringthe formation of the second folded portion by the inner pusher member226. This type of arrangement would avoid the necessity of having toextend the plug 224 downwardly via top cylinder 206 in a separate stepas described above.

Other modifications in accordance with the invention relate to the shapeof the container side wall. For example, the apparatus as describedabove may be utilized to form a collapsed and folded container asillustrated in FIGS. 6, 14 or 16 from a container having a smoothtapered surface or from a container having a smooth cylindrical surface.In the former case, the natural taper of the side wall provides thefrictional engagement with the lower edge 248 of the outer pusher member244 required to initiate the folding action. In the latter case, theintroduction of air under pressure prior to commencing thecollapsing/folding operation, can be used to bulge the side wall of thecontainer outwardly, again providing the frictional engagement necessaryto initiate folding.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. Apparatus for collapsing and folding an uprightcontainer to a compact stackable configuration, the container having abottom wall, peripheral side wall with at least upper, lower andintermediate annular stepped portions in the peripheral side wall, and atop wall having a discharge opening therein, the apparatuscomprising:means for supporting and holding the container in an uprightposition; first forming means for engaging and exerting a downward forceon the intermediate annular stepped portion of the peripheral side walland for effecting the formation of a first folded portion in theperipheral side wall; and second forming means for engaging and exertinga downward force on the top wall for effecting the formation of a secondfolded portion in the peripheral side wall substantially concentric withand radially adjacent the first folded portion.
 2. Apparatus accordingto claim 1 and further including first stop means on said supportingmeans for limiting the downward movement of the first forming means. 3.Apparatus according to claim 2 and further including second stop meanson said first forming means for limiting downward movement of the secondforming means.
 4. Apparatus according to claim 1 and including means forengaging the discharge opening in sealing relationship.
 5. Apparatusaccording to claim 1 and further including means for charging thecontainer with a gas under pressure and for subsequently venting saidgas.
 6. Apparatus according to claim 1 wherein said first forming meanscomprises an outer pusher member having a first platen and asubstantially cylindrical skirt portion depending therefrom. 7.Apparatus according to claim 6 wherein said second forming meanscomprises an inner pusher member having a second platen and asubstantially cylindrical lower portion, arranged for sliding movementwithin said outer pusher member.
 8. Apparatus according to claim 7 andincluding a pair of cylinder assemblies for resiliently biasing saidinner and outer pusher members away from each other.
 9. Apparatusaccording to claim 8 and including a main cylinder assembly having apiston attached at one end to said inner pusher member and having meansfor overriding said pair of cylinder assemblies.
 10. Apparatus accordingto claim 1 and including expandable plug means for insertion andexpansion within the discharge opening of the container.
 11. Apparatusaccording to claim 10 and including means for effecting expansion ofsaid plug means.